--- title: "Configuring IP aliasing" description: "Learn how to add Additional IP addresses to your network configuration." url: https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/configuring-ip-aliasing lang: en --- > For AI agents: the complete documentation index is available at https://docs.us.ovhcloud.com/en/llms.txt, the full documentation bundle is available at https://docs.us.ovhcloud.com/en/llms-full.txt. # Configuring IP aliasing **Learn how to add Additional IP addresses to your network configuration.** IP aliasing is a special network configuration for your OVHcloud dedicated servers, which allows you to associate multiple IP addresses with a single network interface. **Note:** This article is about Additional IPv4 configuration on a public interface. You can also configure Primary IPv6 addresses on your dedicated servers using [this guide](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/network-ipv6.md). Please note that Additional IP addresses can also be configured in a vRack (private network), which allows interconnection over a wide range of OVHcloud services, offering more flexibility. Learn how to configure Additional IP addresses in a vRack with our guides for [IPv4](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack.md) and [IPv6](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/configure-ipv6-in-vrack.md). **Warning:** **NOTE:** OVHcloud provides services for which you are responsible for their configuration and management. You are therefore responsible for their proper functioning.\ \ This tutorial is designed to help you as much as possible with common tasks. If you are having difficulty performing these actions, please contact a specialized service provider. OVHcloud cannot provide you with technical support in this regard.   ## Requirements - A [dedicated server](https://us.ovhcloud.com/bare-metal/) in your OVHcloud account - An [Additional IP address](https://us.ovhcloud.com/network/additional-ip/) or an Additional IP block (RIPE or ARIN) - Access via SSH or remote desktop connection for Windows - Basic networking and administration knowledge **Warning:** This feature might be unavailable or limited on servers of the [Eco product line](https://eco.us.ovhcloud.com/about-us/). Please visit our [comparison page](https://eco.us.ovhcloud.com/compare/) for more information.   ## Instructions The following sections contain configurations for the distributions we currently offer and the most commonly used distributions/operating systems. The first step is always to log in to your server via SSH or a GUI login session (RDP for a Windows server). **Note:** Concerning different distribution releases, please note that the proper procedure to configure your network interface, as well as the file names, may have been subject to change. We recommend consulting the manuals and knowledge resources of the respective OS versions if you experience any issues. **Please take note of the following terminology that will be used in code examples and instructions of the guide sections below:** | Term | Description | Examples | | ------------------ | -------------------------------------------------------------------------------------------------------- | -------------- | | ADDITIONAL\_IP | An Additional IP address assigned to your service | 203.0.113.1 | | NETWORK\_INTERFACE | The name of the network interface | _eth0_, _ens3_ | | ID | ID of the IP alias, starting with _0_ (depending on the number of additional IPs there are to configure) | _0_, _1_ | In the examples below, we will use the `nano` text editor. With some operating systems, you will need to install it first before using it. If this is the case, you will be prompted to do so. You can, of course, use the text editor of your choice. **Tip:** **Select the tab corresponding to your operating system.** ### Debian 11 ### Debian 11 By default, the configuration files are located in `/etc/network/interfaces.d/`. We recommend that you start by backing up the relevant configuration file.   #### Step 1: Create a backup In our example, our file is called `50-cloud-init`, so we make a copy of the `50-cloud-init` file using the following command: ```bash sudo cp /etc/network/interfaces.d/50-cloud-init /etc/network/interfaces.d/50-cloud-init.bak ``` In case of a mistake, you will be able to revert the changes using the commands below: ```bash sudo rm -f /etc/network/interfaces.d/50-cloud-init sudo cp /etc/network/interfaces.d/50-cloud-init.bak /etc/network/interfaces.d/50-cloud-init ```   #### Step 2: Edit the configuration file **Note:** Note that the names of the network interfaces in our examples may differ from your own. Please adjust to your appropriate interface names. You can now modify the configuration file: ```bash sudo nano /etc/network/interfaces.d/50-cloud-init ``` Next, you need to add a virtual interface or ethernet alias. In our example, our interface is called `eth0`, so our alias is `eth0:0`. Do this for each additional IP you wish to configure. Do not modify the existing lines in the configuration file; simply add your Additional IP to the file as follows, replacing `ADDITIONAL_IP/32` as well as the virtual interface (if your server is not using **eth0:0**) with your own values: ``` auto eth0:0 iface eth0:0 inet static address ADDITIONAL_IP netmask 255.255.255.255 ``` Alternatively, you can configure your Additional IP by adding the following lines in the configuration file: ``` post-up /sbin/ifconfig eth0:0 ADDITIONAL_IP netmask 255.255.255.255 broadcast ADDITIONAL_IP pre-down /sbin/ifconfig eth0:0 down ``` With the configuration above, the virtual interface is enabled or disabled whenever the `eth0` interface is enabled or disabled. If you have two Additional IPs to configure, the `/etc/network/interfaces.d/50-cloud-init` file should look like this: ``` auto eth0 iface eth0 inet dhcp auto eth0:0 iface eth0:0 inet static address ADDITIONAL_IP1 netmask 255.255.255.255 auto eth0:1 iface eth0:1 inet static address ADDITIONAL_IP2 netmask 255.255.255.255 ``` Or like this: ``` auto eth0 iface eth0 inet dhcp # IP 1 post-up /sbin/ifconfig eth0:0 ADDITIONAL_IP1 netmask 255.255.255.255 broadcast ADDITIONAL_IP1 pre-down /sbin/ifconfig eth0:0 down # IP 2 post-up /sbin/ifconfig eth0:1 ADDITIONAL_IP2 netmask 255.255.255.255 broadcast ADDITIONAL_IP2 pre-down /sbin/ifconfig eth0:1 down ``` ##### Configuration example: ``` auto eth0 iface eth0 inet dhcp auto eth0:0 iface eth0:0 inet static address 203.0.113.1 netmask 255.255.255.255 ``` Or : ``` auto eth0 iface eth0 inet dhcp # IP 1 post-up /sbin/ifconfig eth0:0 203.0.113.1 netmask 255.255.255.255 broadcast 203.0.113.1 pre-down /sbin/ifconfig eth0:0 down ```   #### Step 3: Restart the interface To restart the interface, use the following command: ```bash sudo /etc/init.d/networking restart ``` ##### Fedora 42+ ### Fedora 42 and following Fedora now uses keyfiles. NetworkManager previously stored network profiles in ifcfg format in this directory: `/etc/sysconfig/network-scripts/`. However, the ifcfg format is now deprecated. By default, NetworkManager no longer creates new profiles in this format. The configuration file is now found in `/etc/NetworkManager/system-connections/`.   #### Step 1: Create a backup **Note:** Note that the name of the network file in our example may differ from your own. Please adjust to your appropriate name. First, make a copy of the configuration file, so that you can revert at any time. In our example, our configuration file is called `cloud-init-eno1.nmconnection`. ```bash sudo cp -r /etc/NetworkManager/system-connections/cloud-init-eno1.nmconnection /etc/NetworkManager/system-connections/cloud-init-eno1.nmconnection.bak ```   #### Step 2: Edit the config file **Note:** Please note that the name of the network file in our example may differ from yours. Please adapt the commands to your file name. To obtain the name of your network interface to edit the appropriate network file, you can run one of the following commands: ```bash ip a ``` ```bash nmcli connection show ``` Do not modify the existing lines in the configuration file; add your Additional IP to the file as follows, replacing `ADDITIONAL_IP/32` wih your own values: ```bash sudo nano /etc/NetworkManager/system-connections/cloud-init-eno1.nmconnection ``` ``` [ipv4] method=auto may-fail=false address1=ADDITIONAL_IP/32 ``` If you have two Additional IPs to configure, the configuration should look like this: ``` [ipv4] method=auto may-fail=false address1=ADDITIONAL_IP1/32 address2=ADDITIONAL_IP2/32 ``` ##### Configuration example: ``` [ipv4] method=auto may-fail=false address1=203.0.113.1/32 ```   #### Step 3: Restart the interface You now need to restart your interface: ```bash sudo systemctl restart NetworkManager ``` ##### Debian 12 & Ubuntu 20.04+ ### Debian 12, Ubuntu 20.04 and later By default, the configuration files are located in the `/etc/netplan` directory. The best practice approach is to create a separate configuration file to set up Additional IP addresses. This way, you can easily revert the changes in case of an error.   #### Step 1: Determine the interface ```bash ip a ``` Note the name of the interface (the one on which your server's main IP address is configured).   #### Step 2: Create and edit the configuration file Next, create a configuration file with a `.yaml` extension. In our example, our file is called `51-cloud-init.yaml`. ```bash sudo nano /etc/netplan/51-cloud-init.yaml ``` Edit the file with the content below, replacing `INTERFACE_NAME` and `ADDITIONAL_IP` with your own values: ```yaml network: version: 2 ethernets: INTERFACE_NAME: dhcp4: true addresses: - ADDITIONAL_IP/32 ``` If you have two Additional IPs to configure, the configuration file should look like this: ```yaml network: version: 2 ethernets: INTERFACE_NAME: dhcp4: true addresses: - ADDITIONAL_IP1/32 - ADDITIONAL_IP2/32 ``` **Warning:** **NOTE:** It is important to respect the alignment of each element in this file as represented in the example above. Do not use the tab key to create your spacing. Only the space key is needed. ##### Configuration example: ```yaml network: version: 2 ethernets: eth0: dhcp4: true addresses: - 203.0.113.1/32 ``` Save and close the file. You can test the configuration with the following command: ```bash sudo netplan try ```   #### Step 3: Apply the change If it is correct, apply it using the following command: ```bash sudo netplan apply ``` **Note:** When using the `netplan try` command, it is possible that the system returns a warning message such as `Permissions for /etc/netplan/xx-cloud-init.yaml are too open. Netplan configuration should NOT be accessible by others`. This simply means that the file does not have restrictive permissions. This does not affect the configuration of your Additional IP. For more information about file permissions, consult the [official documentation of Ubuntu](https://help.ubuntu.com/community/FilePermissions). ##### Alma Linux / Rocky Linux ### AlmaLinux (8/9/10), Rocky Linux (8/9/10) The main configuration file is located in `/etc/sysconfig/network-scripts/`. In this example, it is called `ifcfg-eth0`. Before making changes, verify the actual file name in this folder. For each Additional IP to be configured, we create a separate configuration file with the following parameters: `ifcfg-NETWORK_INTERFACE:ID`. Where `NETWORK_INTERFACE` is the physical interface and `ID` is the virtual network interface or ethernet alias starting with a value of 0. For example, for our interface named `eth0` the first alias is `eth0:0`, the second alias is `eth0:1`, etc.   #### Step 1: Determine the interface ```bash ip a ``` Note the name of the interface (the one on which your server's main IP address is configured).   #### Step 2: Create the configuration file First, create the configuration file. Replace `NETWORK_INTERFACE:ID` with your own values. ```bash sudo nano /etc/sysconfig/network-scripts/ifcfg-NETWORK_INTERFACE:ID ``` Next, edit the file with the content below, replacing `NETWORK_INTERFACE:ID`, and `ADDITIONAL_IP` with your own values: ``` DEVICE=NETWORK_INTERFACE:ID ONBOOT=yes BOOTPROTO=none # For CentOS use "static" IPADDR=ADDITIONAL_IP NETMASK=255.255.255.255 BROADCAST=ADDITIONAL_IP ``` ##### Configuration example: ``` DEVICE=eth0:0 ONBOOT=yes BOOTPROTO=none # For CentOS use "static" IPADDR=203.0.113.1 NETMASK=255.255.255.255 BROADCAST=203.0.113.1 ```   #### Step 3: Restart the interface Next, restart the network interface with the following command: ```bash sudo systemctl restart NetworkManager ``` ##### cPanel ### cPanel #### Step 1: Access the WHM IP management section In the WHM control panel, click on `IP Functions` and select `Add a New IP Address` in the left-hand sidebar.   #### Step 2: Add the Additional IP information Enter your Additional IP in the form `xxx.xxx.xxx.xxx` into the field “New IP or IP range to add”. Select `255.255.255.255` as your subnet mask, then click on `Submit`. **Warning:** **NOTE:** Please note that if you have more than one IP to configure on the same block and you add them all at once, the WHM system will force you to use the subnet mask `255.255.255.0`. We do not recommend using this configuration. Instead, you need to add each IP individually to use the proper subnet mask `255.255.255.255`.   #### Step 3: Check the current IP configuration Back in the section `IP Functions`, click on `Show or Delete Current IP Addresses` to verify that the Additional IP address was added correctly. ##### Windows ### Windows Servers Windows servers are often DHCP-enabled in the network configuration. If you have already set up an Additional IP or switched your configuration to a fixed IP, go directly to the next step. Otherwise, you need to first switch from a network-level DHCP configuration to a fixed IP configuration. Open the command prompt `cmd` or `powershell`, then type the following command: ``` ipconfig ``` This will return a result similar to the following example: Identify and write down your IPv4, subnet mask, default gateway, and the name of the network interface controller (network adapter). In our example, the server IP is **192.0.2.28**. You can perform the next steps via either a command-line interface or the graphical user interface. #### Via a command-line interface (recommended) In the commands below, you need to replace: | Command | Value | | ---------------- | --------------------------------------------------------------------- | | NETWORK\_ADAPTER | Name of the network adapter (in our example: Ethernet 2) | | IP\_ADDRESS | Server IP address (in our example: 192.0.2.28) | | SUBNET\_MASK | Subnet mask (in our example: 255.255.255.0) | | GATEWAY | Default gateway (in our example: 192.0.2.254) | | ADDITIONAL\_IP | Address of Additional IP you want to add (in our example 203.0.113.1) | **Warning:** **NOTE:** Be careful – the server will no longer be accessible if you enter incorrect information. You will then have to make the corrections in [Winrescue mode](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/rescue-mode.md) or via the [IPMI](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/use-ipmi-console.md). In the command prompt: 1\. Switch to a fixed IP ``` netsh interface ipv4 set address name="NETWORK_ADAPTER" static IP_ADDRESS SUBNET_MASK GATEWAY ``` 2\. Set the DNS server ``` netsh interface ipv4 set dns name="NETWORK_ADAPTER" static 213.186.33.99 ``` 3\. Add an Additional IP ``` netsh interface ipv4 add address "NETWORK_ADAPTER" ADDITIONAL_IP 255.255.255.255 ``` Your Additional IP is now functional. #### Via the graphical user interface 1. Go to `Start`> `Control Panel`>`Network and Internet`> `Network and Sharing Centre`> `Change Adapter Settings`(in the left-hand menu). 2. Right-click on your network connection, in our example `Ethernet 2`. 3. Click on `Properties`. 4. Select `Internet Protocol Version 4 (TCP/IPv4)`, then click on `Properties`. 5. Click on `Use the following IP address` and type in your server’s primary IP, subnet mask, and default gateway information obtained by using the `ipconfig` command above. In the "Preferred DNS Server" box, type 213.186.33.99. **Warning:** **NOTE:** Be careful – the server will no longer be accessible if you enter incorrect information. You will then have to make the corrections in [Winrescue mode](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/rescue-mode.md) or via the [IPMI](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/use-ipmi-console.md). Then click on `Advanced` (still in the `TCP/IP Settings`). In the `IP Address` section, click `Add`: Type in your Additional IP and the subnet mask **255.255.255.255**. Then click on `Add` Click on `OK` to apply your configuration. Your Additional IP is now functional; you can verify the configuration with the following command: ``` ipconfig ``` This will return a result similar to the following example: ##### Plesk ### Plesk #### Step 1: Access the Plesk IP management section In the Plesk control panel, choose `Tools & Settings` from the left-hand sidebar. Click on `IP Addresses` under **Tools & Resources**.   #### Step 2: Add the Additional IP information In this section, click on the button `Add IP Address`. Enter your Additional IP in the form `xxx.xxx.xxx.xxx/32` into the field "IP address and subnet mask", then click on `OK`.   #### Step 3: Check the current IP configuration Back in the section "IP Addresses", verify that the Additional IP address was added correctly.   ### Troubleshooting In some cases, you need to reboot your server if restarting the interface does not work. Restart your server from the command line or its GUI. If you are still unable to establish a connection from the public network to your Additional IP and suspect a network problem, you need to reboot the server in [rescue mode](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/rescue-mode.md). Then you can set up the Additional IP address directly on the server. Once you are connected to your server via SSH, enter the following command: ```bash ifconfig eth0:0 ADDITIONAL_IP netmask 255.255.255.255 broadcast ADDITIONAL_IP up ``` To test the connection, simply ping your Additional IP from the outside. If it responds in rescue mode, that probably means that there is a configuration error. If, however, the IP is still not working, please [open a ticket with the support team](https://docs.us.ovhcloud.com/en/account/account-information/contact-us-support.md) with the following information: It is necessary to provide: - The operating system name and version you are using on your server. - The name and directory of the network configuration file. - The content of that file.   ## Go further [Configuring a network bridge](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/network-bridging.md) Browse all the [Dedicated Servers guides](https://docs.us.ovhcloud.com/en/bare-metal-cloud/dedicated-servers/landing-page-dedicated-servers.md). Browse the rest of the [OVHcloud US documentation](https://docs.us.ovhcloud.com/en/index.md) for guides on our other products and services. Learn more about [Dedicated Servers](https://us.ovhcloud.com/bare-metal/) on the OVHcloud US website.